Any way to allow a 3.5" bore through a 2x10 floor joist?

I need to bore a hole in a 2x10 floor joist to accomodate a 3" PVC pipe, the outside diameter of which is 3.5". I know the code dicates that holes in floor joists can be no greater than 1/3 the depth of the joist. So for a 2x10 joist, the actual depth is 9.25, which means that the specified hole shouldn't be any bigger than about 3". Is there any way to be code compliant in drilling a 3.5" hole? Some sort of joist reinforcement perhaps? The joist in question is really more of a "ledger board", in that it's supported not only by beams, but it's also located flush against a joist of an existing structure and fastened with wood screws (not lag screws, but that could be remedied). Any suggestions or tips?

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Any way to allow a 3.5" bore through a 2x10 floor joist?

Quote:

Originally Posted by peeks

I need to bore a hole in a 2x10 floor joist to accomodate a 3" PVC pipe, the outside diameter of which is 3.5". I know the code dicates that holes in floor joists can be no greater than 1/3 the depth of the joist. So for a 2x10 joist, the actual depth is 9.25, which means that the specified hole shouldn't be any bigger than about 3". Is there any way to be code compliant in drilling a 3.5" hole? Some sort of joist reinforcement perhaps? The joist in question is really more of a "ledger board", in that it's supported not only by beams, but it's also located flush against a joist of an existing structure and fastened with wood screws (not lag screws, but that could be remedied). Any suggestions or tips?

I drill 2x10's all the time for three inch pvc. Yeah, they like to see the holes as close to the center as possible and usually three feet from the end. But, where you have it sistered up to something else it sounds OK to me!